The present invention relates to an indicating device for providing an indication of the relative angle between a coupled towed vehicle and towing vehicle.
When backing up with an automobile, or any other similar towing vehicle, having a coupled towed vehicle attached to the rear bumper, it is often a problem trying to keep the towed vehicle in alignment along the same longitudinal axis as the automobile. In order to assist in this procedure, it is desirable if the person within the automobile knows the exact relative angle between the towed vehicle and the automobile. For this purpose, it is desirable to provide some type of visual indicator which can be seen by the person in the automobile as he proceeds to back up.
Several devices have been developed within the prior art for accomplishing this basic objective. One type of device is a mechanically operated indicator which provides an indication of this angular relationship, which indication can be seen in the rear view mirror of the person driving the automobile. Such a device is illustrated in U.S. Pat. No. 2,736,885 issued to Thompson. There also have been developed in the past few years, several electrical indicating devices for the purpose of providing an indication of the relative angular relationship between the two vehicles. Such devices are illustrated in U.S. Pat. Nos. 3,605,088 and 3,833,928 issued to Savelli and Gavit el al., respectively.
When backing up a boat trailer, it also becomes desirable to have some type of indication as to when the trailer has reached a proper depth within the water for launching of the boat. Thus, the present invention is concerned with providing a water sensing indicator capable of providing such an indication.
While U.S. Pat. No. 3,585,582 issued to Dove illustrates an indicator which senses when a trailer has reached a certain depth in the water, this indicator is provided below the wheel hub assembly and is utilized for providing a warning signal before the hub assembly comes into contact with the water. Such an indicator, however, cannot be utilized on a trailer for launching a boat since almost the entire trailer must be submerged in the water for proper launching.